The purpose of this study is to compute the cost efficiency of international tourist hotels ( ITHs) in Taiwan and analyze how regional environmental quality affects cost efficiency. The study collects a variety of operating data of international tourist hotels in Taiwan between 1998 and 2009 from the Annual Tourist Hotels Operational Analysis Report, as published by the Tourism Bureau. The data of regional environmental quality are collected from the Taiwan Environment Data Warehouse. This study first uses data envelopment analysis ( DEA) for computing cost efficiency, and then applies the truncated regression to investigate the impact of environmental indicators on cost efficiency. Namely, it is a two-stage DEA-regression method. The empirical results indicate that the density of pungent air pollutants, such as O 3 and SO 2 , have significantly negative impacts on the cost efficiency of ITHs in Taiwan. However, the high volume of waste disposal and low recycling rate reflect a higher business activity intensity in a region, which positively enhances ITHs' cost efficiency.